A multi-ply yarn such as a novelty yarn, a double yarn, a flame yarn, a boucle yarn, a knob yarn or the like is made by winding together several strands, with the individual strands being fed to the winding-together location at different speeds. Frequently the strands are different types of yarns.
The standard apparatus for making such a multi-ply yarn has a plurality of strand-feed elements that can each be driven by a respective drive. Normally each such drive must be capable of operating at two separate speeds, and must be capable of stopping when desired. Thus the drives normally comprise complicated transmissions capable of driving the strand-feed elements at the desired speeds.
An enormous disadvantage of this system is that it is an extremely complex matter to set up so as to produce a given effect. The transmissions are normally dismantled, with gears being switched, and other changes to the mechanism must be made each time a new novelty yarn is to be produced. What is more each such setting-up requires that the machine be brought to a complete standstill and virtually be rebuilt. Obviously the expense and bother of such an arrangement is enormously disadvantageous.